Milton H. Greene might not be a name you instantly recognize, but you certainly have seen his work. Throughout his four-decade-long career, the celebrated photographer shot some of the biggest and most iconic celebrities from the Golden Age of Hollywood, including Marlene Dietrich, Frank Sinatra, Grace Kelly, Cary Grant, Elizabeth Taylor, and Audrey Hepburn. But Greene is probably best known for his work with Marilyn Monroe, who he befriended in 1953 after photographing her for Look magazine. Over the course of four years, not only would Greene take some of the most recognizable photos of the legendary actor (during 50 photo sessions), but he would also help get her out of her contract with 20th Century Fox and go on to create Marilyn Monroe Productions, Inc. with her (where they went on to produce two films together).

Recently Greene’s son, Joshua Greene, compiled and restored some of his father’s best-known photographs of Monroe (Greene died in 1985), as well as never-before-seen shots, for a new retrospective book, The Essential Marilyn Monroe: Milton H. Greene, 50 Sessions. BuzzFeed got a look at some of the photos from the book, as well as some behind-the-scenes tidbits.

"Ballerina" (October 1954)

Easily the most iconic shoot Greene did with Monroe. The reason she is seen holding up her bodice throughout the photos is because Greene's wife, Amy, had bought it for the shoot, but it was two sizes too small — so she could not zip it up and was forced to hold it in place.

"Nude" (1953)

This was taken during the very first sitting they did together for Look magazine. Monroe is seen here wearing just Greene's wife's sweater. While this is pretty tame by today's standards, it was actually considered risqué for a mainstream magazine at the time. Also, she is sitting in the photo due to a sprained ankle.

"Gypsy" (1953)

Monroe raided the wardrobe department at 20th Century Fox and decided to dress up as a gypsy palm reader (problematic, I know). Greene then photographed her in the facade of a psychic shop in the backlot.

"Prince and the Showgirl" (July/August 1956)

This photo of Monroe alongside her co-star and director Laurence Olivier was taken on the set of their film The Prince and the Showgirl. Greene and Monroe produced the movie through their company, Marilyn Monroe Productions, Inc.

"Black Cape" (October 1955)

Greene captured this as he tested lighting for a shoot he was going to do the next day and used Monroe as a model. She is wearing a cape that had been left over from a fashion shoot Greene had done earlier that day.